Use of electronic steering systems in boats has become very popular. Such systems are used to maintain a target heading by a boat without requiring a person to steer the boat.
The basic function of any electronic steering system of a boat is to establish and generally maintain a predetermined (target) heading of the boat by adjusting the current heading of the boat in response to deviations of the current heading from the predetermined (target) heading. A variety of electronic steering systems are disclosed in U.S. Pat. Nos. 4,103,638 issued to Fowler; 3,965,840 issued to Blumberg; 4,590,570 issued to Rader; and 4,542,464 and 4,564,909 issued to Kramer.
These known systems are generally used with stern-mounted motors. In order to direct a boat having a stern-mounted motor to a target heading, the direction of thrust of the motor must be in a direction other than the target direction. Furthermore, as the current heading of the boat approaches the target heading, the difference between the direction of thrust and the target heading of the boat must be reduced, in order to prevent the current heading of the boat from greatly overshooting the target heading. Thus, electronic steering systems used with stern-mounted motors require two direction sensors, one to sense the current heading of the boat, and one to sense the direction of the thrust of the motor relative to the current heading of the boat. The hardware and software of an electronic steering system used with a stern-mounted system must be able to determine if a steering correction is needed, the direction of the steering correction, and the magnitude of the steering correction. The magnitude of the steering correction is needed to set the difference between the direction of thrust of the motor and the current heading of the boat, and adjust this difference as the current heading of the boat approaches the target heading. The use of two sensors, as well as hardware and software capable of changing the magnitude of correction, increases the cost of the electronic steering system.
Some known systems require external radio signals to determine the location of the boat, and then calculate the correction necessary to maintain the target heading. Systems such as these may be useful on boats travelling great distances in large bodies of water but are unnecessarily elaborate and expensive for use on boats travelling on small lakes.
The electronic steering system of the present invention is adaptable to be used on a bow-mounted motor and advantageously requires a single direction sensor. Also, the hardware and software required to implement the electronic steering system of the present invention need only be capable of determining whether a steering correction is needed and the direction of the correction. The electronic steering system of the present invention is easy to use, including a manual override feature. Furthermore, the present invention internally provides signals corresponding to both the predetermined heading and the current heading, to obviate the need for external radio signals indicating location, thus making the electronic steering system less complicated and less expensive.
Therefore, an object of the electronic steering system of the present invention is to be adaptable for use on a bow-mounted motor and advantageously requires a single direction sensor. Furthermore, it is an object of the present invention that the hardware and software required to implement the electronic steering system of the present invention need only be capable of determining whether a steering correction is needed and the direction of the correction, and that a manual override is included. Another object of the present invention is that signals corresponding to both the predetermined heading and the current heading are provided internally, to obviate the need for external radio signals indicating location.